If you saw my recent post about malformed circles, you’ll see that I was pulling my hair out. I identified the root cause. It turns out that I was writing 0x00000fff, which caused the pixel I was setting to be...
Archive - April 2017
Graphics Primitives are working, at least mostly.
So we’ve got a frame buffer now which means we can start writing 68K routines to write graphics into it. So here I’m playing around with lines and circles. I’m using a random line drawing routine from...
Frame Buffer and Text Generation now working…
Now that I have the 4MB SRAM board installed, I now have a frame buffer that can keep up with the video bandwidth rate. The resolution and color depth is currently 800 x 480 x 12-bit. The computing shield I’m...
Interesting snippet from FPGA Prototyping by Chu
This is exactly the problem that I’ve been facing for the last couple weeks. I could get the memory tests to pass at 100% if only the CPU was talking with the external SRAM. As soon as I added in my time slot...
SRAM Frame Buffer is now up and running!
Exciting times for the Hope Badge Computer. Tonight, I’ve worked out most of the kinks with interfacing the new SRAM module which you can see in posts below this, to the J68 soft-core CPU. This means that I can...